1. Field of the Invention
This invention relates to electrical devices.
2. Introduction to the Invention
Ser. No. 08/121,717 and its published International counterpart WO 94/01876 disclose circuit protection devices which comprise first and second laminar electrodes; a laminar PTC resistive element sandwiched between the electrodes; a third laminar conductive member which is secured to the same face of the PTC element as the second electrode but is separated therefrom; and a cross-conductor which passes through an aperture in the PTC element and connects the third conductive member and the first electrode. This permits connection to both electrodes from the same side of the device, so that the device can be connected flat on a printed circuit board, with the first electrode on top, without any need for lead. The resistive element preferably comprises a laminar element composed of a PTC conductive polymer. Preferably the device comprises an additional conductive member and an additional cross-conductor, so that the device is symmetrical and can be placed either way up on a circuit board. Ser. No. 08/242,916 and its published International counterpart WO 95/31816 describe improved devices of the kind described in Ser. No. 08/121,717 which include insulating members which prevent solder bridges between the conductive member and the adjacent electrode. Ser. No. 08/257,586 and its published International counterpart WO 95/34084 describe an improved method of making such devices. The entire disclosure of each of those U.S. applications and International Publications is incorporated herein by reference for all purposes.